Yellow Foxglove features bold spikes of buttery yellow bell-shaped flowers with yellow eyes and brown spots rising above the foliage from late spring to mid summer. The flowers are excellent for cutting. Its pointy leaves remain green in color throughout the season.
Yellow Foxglove is an herbaceous perennial with a rigidly upright and towering form. Its medium texture blends into the garden, but can always be balanced by a couple of finer or coarser plants for an effective composition.
Yellow Foxglove will grow to be about 24 inches tall at maturity extending to 3 feet tall with the flowers, with a spread of 18 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 15 inches apart. It tends to be leggy, with a typical clearance of 1 foot from the ground, and should be underplanted with lower-growing perennials. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 5 years. As an herbaceous perennial, this plant will usually die back to the crown each winter, and will regrow from the base each spring. Be careful not to disturb the crown in late winter when it may not be readily seen!
This plant does best in full sun to partial shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This species is not originally from North America, and parts of it are known to be toxic to humans and animals, so care should be exercised in planting it around children and pets.
Yellow Foxglove is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. With its upright habit of growth, it is best suited for use as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. It is even sizeable enough that it can be grown alone in a suitable container. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.